Various types of fluid couplings are employed in fluid circuits. Such fluid couplings are typically employed to connect together separate components of a fluid system, such as when a first tube is connected together with a second tube or with another structure such as a manifold block. Such fluid couplings generally are designed to provide substantially leak-free seals between connected components in a given environment.
Fluid couplings often include components that are tightly threaded together to provide the substantially leak-free seal. The threaded configuration of the components permits them to be easily connected together to assemble the hydraulic circuit, and are readily separated from one another, such as when the various components of the hydraulic circuit are in need of inspection, maintenance, and/or replacement.
One such type of environment in which fluid couplings are employed is in a hydraulic circuit. Hydraulic circuits typically involve the transfer of fluids at high temperatures and pressures in the presence of extreme vibrations. While known hydraulic couplings have been generally effective for their intended purposes, such hydraulic couplings have not been without limitation.
The high vibration environment of a hydraulic circuit, combined with the expansions and contractions of the components of a hydraulic circuit resulting from temperature changes and high pressures, causes the threaded portions of hydraulic fittings to gradually loosen, i.e., unthread, over time. Generally any loosening of a coupling will result in a leakage of the fluid from within the circuit, and progressively greater degrees of loosening typically cause progressively greater rates of fluid loss. It is thus highly desirable to provide a hydraulic fitting with a self-locking feature that resists unthreading in the typical hydraulic environment of high temperatures, pressures, and vibration.